Automatic die casting machine



July 27, 1948. R. BOURRET ET AL AUTOMATIC DIE CASTING MACHINE Filed July11,- 1946 2 Sheets-Sheet 1 1 7\ F2 v aw I X L- 6 RENE 150mm and JACQUESBARDOU V I I Inventors P J Attorneys July 27, 1948. BQURRET r AL2,445,995

AUTOMATIC DIE CASTING MACHINE Filed July 11, 1946 2 Sheets-Sheet 2 RENEBOURRET and JACQUES mnnou"- Inventor;

Attorneys Patented July 27, 1948 UNITED STATES 2,445,995 AUTOMATIC DIE.CASTING Rene Bourret, Boulogne-sur-seine -and Jacques Bardou; Paris,France, assignors to Societe dApplications Mecaniques pourIAutongfobile, Boulogne-sur-Seine, France, va -corporation of:-

France Application July 11,.1946,SerialNoi 682,9'68' In FranceNovember-1945" In operations for casting metal pieces and, moreparticularly, in operations for die casting it isressential that theextraction of the cores be effected according to a fixed time schedulefor each'shape of casting, in order toavoid certain casting: accidentsdue to shrinking phenomena. It has beenproposed to make this schedule ofextraction more precise by putting at the disposal of the foundryworkman an apparatus which,

through emitting a series of signals spaced in a predetermined manner,indicates the moments outer element of the chill is fast with a piston.

actuated by a compressed fluid, the distribution of said compressedfluid to the various pistons taking place by a single slide valvecontrolled by the rotation of a cam preferably rotating at a constantspeed, the respective shapes and: arrangements :of said slide valve andsaid'cam being d-etermin'ed in a manner known per se within the reach ofany man skilled in the art. It is thus possible by using a cam withapredetermined profile chosen according to the operation to be efiectedto ensure the sequence of the operations for extraction of the cores andthe removal of the castings fromthe mould through the rotational? thecamat a constant speediwithout the operator having to intervene from themoment when the machine has been started.

According to a preferred form of execution of the invention the pistonsactuating each outer element and the core or spindle which passesthrough the same, as the case may be, are combined into a single onewhich is arranged so that the die element is displaced only after thecore has been entirely released from the casting.

Finally, the tilting movement of the casting table after the withdrawalof the casting from the mould is preferably ensured in the same mannerthrough a compressed fluid actuated piston controlled by the samedistribution slide Valve.

The appended drawings show examples of execution of die casting machinesaccording to the invention. In these drawings, in which for avoid- 1Claim. (01. 22-432) ing complication. of :therfigures the" conduitstion.

thedistribut'ion-of the-fluidxhave notbeenfshowm.. Fig; 1 is adiagrammatical viewwpartlyrrmv plea vation: and spartlynwin sectionthrough 1111 .clie' .compriseaiion the piecew i being castg'; threeoutertelement's 5-; 6 oreziBL d lateral rspiiidles.r9; spindle forms; a

mounted in: ancylinder tom lofd said cylinder and whichfi's l the die:el-ement; furthermorexthe :rod 1-5 'comprisesi ashould'eril 'l. Y l

When compressed air i introduced "into tlie cylinder I4 through thepipingppening at flflthe pressure first exerted on the faces o'f tliepistons i3 and I 6} tends to separate them and-the piston i 3 "movesalone carryingwith it the core 9"when the shoulder W comes to "strikeagainst"the-"Walt of the piston T6 the latter is-rendered 'faiSt'iWiththe piston 13 and the whole "movesfurtl'r'ery thus" carrying with it thedie element.

The central core 8 is fast with the rod of a pisston moving in acylinder Me. On the other hand, the table 3 is maintained by the rod ofa piston moving in a cylinder I41. The compressed fluid is distributedto the Various cylinders [4a, b, c, d, e, ,f by a single slide valveknown per se and not shown, actuated by a cam the shape of which isdetermined, also in a manner known per se, in function of the scheduleaccording to which the successive operations of extraction of the coresand of withdrawal of the castings are to be effected, said cam beingdriven at a constant speed for instance by an electric motor.

A casting operation is carried on in the following manner. On thebeginning of the operation the table 3 is sloped towards the left of thefigure. At the moment when he effects the casting proper of the metal,the operator starts the motor actuating the cam, The latter actuates theslide valve which first determines the supply of compressed fluid to theupper part of the cylinder l4 The, table I returns progressively to ahorizontal position, which determines a correct distribution of themolten metal in the die. After a time which is determined by the profileof the cam the various spindles and the central core are extracted atthe required moments and the casting 4, which is withdrawn from themould, can be removed from the table I. The cam moving further, theslide valve determines the simultaneous operation of the cylinders inthe reverse direction with respect to the preceding one and the variousorgans resume their starting position, the machine thus being ready fora new operation.

\ The machine shown in Figs. 4 and 5 is designed for casting pistonsmade of a light alloy. The

die is formed of two elements l9 and 20 and the casting is effected onthree cores, viz. a central core with counter-delivery and two sidespindles providing the recesses for the axis for the small end of theconnecting rod. The above mentioned core primarily comprises a centralelement having no projections in its part which is to be engaged in thecasting and one or more, preferably two, side elements between oragainst which the central element can slide and which are linked aboutaxes perpendicular to the direction of displacement of the latter. Thelatter is provided with sloping surfaces co-acting with stops carried bythe side elements for determining the rocking movement of the latterabout their axis of articulation while moving nearer to the centralelement when the latter yields back between the said side elements whichare recessed inwardly-for permitting this rocking movement. Said coreisfast with a piston located in a cylinder2l' while; the side spindles arefast with pistonslocated in cylinders 22 and 23 and mounted, asexplained previously, so that the die element is carried along after thecore has been extracted.

. The machine is provided, furthermore, with vibrators 24 and 25 mountedon the die elements and adapted for being started just before thewithdrawal of the casting from the mould in order to facilitate saidoperation. The table I is rockingly mounted on axes 2 carried by a frame3 and a cylinder [4] controls the rocking movement of said table.

All the cylinders are supplied with compressed fluidby a single slidevalve 26 actuated by the rotation, ata constant speed, of a cam 21driven by an electric motor 28 provided with a speedreducing gear 29.Cam 2! controls thestarting andthe stopping of the vibrators also in amanner known per se.

"spindles are extracted and then, the vibrators 24 and 25 having beenstarted, the die elements are separated and finally the central core isextracted; the casting can then be removed. The cycle terminates by thereturn of the core, the

spindles and the die elements to their initial position as well as bythe rocking of the table.

It has been supposed above that the motor which drives the cam runs at aconstant speed,

but this condition of simplicity is not absolutely h necessary. Thespeed of the motor may be rendered variable at will, a rheostat beinginterposed,

for instance, in the supply of the electric motor.

What we claim is:

An automatic die casting machine having cores and dies, a compressedfluid piston and cylinder device for controlling each of said cores andits corresponding die, said piston and cylinder device comprising acylinder having two sections of different cross-sectional area, a pistonin each section, the larger of said pistons being beyond the smallerwith respect to said die, said smaller piston being hollow, and saidlarger piston having a rod passing through said smaller piston andsecured to said core, said smaller piston being secured to said die,means for supplying compressed fluid to said cylinder between saidpistons, said piston rod being provided with a stop within said smallerpiston to limit the relative displacement of said pistons to theapproximate length of the said core.

' RENE BOURRET.

JACQUES BARDOU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,724,332 Will et al Aug. 13,1929 1,896,690 White Feb. 7, 1933 1,925,496 Nichols Sept. 5, 19332,065,213 Dolan et al Dec. 22, 1936 2,171,628 Lannert Sept. 5, 19392,201,906 Lebkuechner May 21, 1940 2,419,373 Schrumn Apr. 22, 1947FOREIGN PATENTS Number Country Date 607,088 Germany Dec. 17, 1934

